Lecture 6 - Adequacy-FunctionalSpring 2010CSci 58022Adequacy: We can’t get what we want•What we would like:–A real way of measuring effective testingIf the system system passes an adequate suite of test cases, then it must be correct (or dependable)•But that’s impossible!–Adequacy of test suites, in the sense above, is provably undecidable.CSci 5802Ch 9, slide 3•So we’ll have to settle on weaker proxies for adequacy–Design rules to highlight inadequacy of test suites Practical (in)Adequacy Criteria•Criteria that identify inadequacies in test suites. – Examples–if the specification describes different treatment in two cases, but the test suite does not check that the two cases are in fact treated differently, we may conclude that the test suite is inadequate to guard against faults in the program logic. –If no test in the test suite executes a particular program statement, the test suite is inadequate to guard against faults in that statement.•If a test suite fails to satisfy some criterion, the obligation that has not been satisfied may provide some useful CSci 5802Ch 9, slide 4information about improving the test suite.•If a test suite satisfies all the obligations by all the criteria, we do not know definitively that it is an effective test suite, but we have some evidence of its thoroughness.